Variable-speed sheave.



' Patented June 0,1902.

E V 5 NE E" 8 N .EH E ms cl B EM R, A V.

(Application filed July 15, 1901.)

(No Model.)

UNITED I STATES PATENT OFFICE.

EMIL CHRISTENSEN, OF PORTLAND, OREGON.

VARIABLE-SPEED SHEAVE.

SPECIFICATION forming part of Letters Patent No. 702,630, dated June 17,1902.

Application filed July 15, 1901.

To all whom it..may concern Be it known that I, EM 1L CHRISTENSEN, acitizen of the United States, residing at Portland, in the county ofMnltnomah and State of Oregon, have invented a new and usefulVariable-Speed Sheave, of which the followingis a specification.

My invention relates to an improvemen invariable speed sheaves fortransmitting power from one shaft to another and increasing ordecreasing the speed of the driven shaft at will without afiecting thespeed of the driving shaft; and it consists in the peculiar constructionand combination of de vices hereinafter fully set forth and claimed.

In the accompanying drawings, Figure 1 is a side elevation of a pair ofmy improved variable-speed sheaves, showing the same respectively on adriving-shaft and a driven shaft and provided with means forsimultaneously operating them, whereby the speed of the driven shaft maybe varied at will without varying the speed of the drivingshaft. Fig. 2is atop plan View of the same, thedriven sheave being shown in section.

I will term the shaft 1 the driving-shaft and the shaft 2 the drivenshaft. A variable-speed sheave 3 issecured on each of the said shafts,the said sheaves being fast thereto. The said sheaves are alike inconstruction, and a description of one of them will suffice for thepurposes of this specification. The central portion a is here shown asforming a circular concavo-convex web, in which at the periphery thereofare radial openings 1), and on opposite sides of each'of the saidopenings are lugs or ears 0. A series of bellcrank levers d, which arepreferably of the form here shown, are pivotally mounted between theears 0, andtheir outer arms 6 are adapted to operate in the openings b.The outer ends of the'said-bell-crank levers carry segments f, which arehere shown as grooved and are adapted to be engaged by a flexibleendless element fortransmitting power from one sheave to another, as anendless belt or an endless cable 4. -The inner ends of the bell-cranklevers engage an annular groove g in a sleeveh, which is splinedon theshaft. It will be understood that by moving the sleeve h inwardly on theshaft toward the web Ct the bell-crank levers will be so turned as to'tions.

Serial No. 68,382. (No model.) I

move the segments f, which form the periphery of the sheave, outwardly,and thereby increase the diameter of the said sheave, and that by movingthe said sleeve in the opposite direction the diameter of-the saidsheave may be decreased. eling power-transmitting element engaged by theperipheral segments of the sheave may be driven at a greater or lowerrate of speed by varying the distance between the said segments and thecenter of the sheave, as will be understood. 1

In practice I provide means for simultaneously reversely adjusting theradial movable segments of the driving and driven sheaves. As hereshown, I provide a pair of bell-crank levers 1 and 2 which arerespectively connected to the sleeves h of the driving and drivenshafts, the said bell-crank levers being disposed in reverse relation toeach other, their fulcrums being indicatedat 5, and the said bell-cranklevers being connected to gether for simultaneous movement by arod 6,which forms. the shifter. Any suitable Hence the endless travmeans, (notshown,) as a lever or the like,

.may be employed for operating the shifter.

ing segments of the other sheave are reversely moved to reduce thediameter thereof, and hence the endless power-transmitting element 4remains effective under allcondione of the shafts to be thedriving-shaft and the other the driven shaft the speed of the latter maybe increased or diminished at will, while the speed of the driving-shaftis unvaried. a

Having thus described my "invention, I claim A g 1. The -combinationof ashaft, a hub ele ment thereon, having radial slots, a plurality ofradially-disposed bell-crank leversdis- It will be understood thatassuming posed transversely of said slots, pivoted to adapted to engagean endlessflexible power-.

transmitting element, a ring to which the inner ends of said bell-cranklevers are pivot= ally connected, and a'shiftable sleeve, on said shaft,having an annular groove engaged by said ring, substantially asdescribed.

of the bell-crank levers, to turn the latter on their pivots and therebyvary the radius of 2. A variable-speed sheave, comprising a the groovedsegments, substantially as dehub element having radial slots, aplurality of radially-disposed bell-crank levers pivoted to said hubelement, having their outer arms disposed in and transversely of theslots and provided at their outer ends with circumferentially-groovedsegments adapted to engage an endless flexible power-transmittingelement, and means, connected to the inner arms scribed.

In testimony that I claim the foregoing as my own I have hereto affixedmysignature in the presence of two Witnesses.

EMIL CHRISTENSEN.

Witnesses:

CHAS. H. KORELL, CHAS. I-IUToHINs.

